Bladder cancer is a type of cancer that occurs in your bladder, a balloon-shaped organ in your pelvic area that stores urine. It is the fourth most common type of cancer in men and the eighth most common type in women. Tumors can develop on the surface of the bladder wall or in more severe cases, within the wall and into the underlying muscles. Cancer in the bladder typically affects older adults, though it can occur at any age. Bladder tumors are 2 to 3 times more common in men.
Causes of Bladder Cancer
Smoking, gender, and diet can affect the risk of developing bladder cancer. Bladder carcinomas are also associated with industrial exposure to aromatic amines in dyes, paints, benzedine, nitrates, solvents, leather dust, inks, combustion products, rubber, and textiles. The period between exposure to the carcinogen and development of symptoms is about 18 years.
There is currently limited evidence that diet plays a part in the development of bladder cancer, but a diet high in fruit and vegetables and low in fat may help reduce the risk. Urinary infections, kidney and bladder stones, and other causes of chronic bladder irritation have been linked with bladder cancer (especially squamous cell carcinoma of the bladder), but they do not necessarily cause bladder cancer.
Signs of Bladder Cancer
In early cases around 25% of patients have no symptoms. Commonly the first sign of bladder tumours is blood in the urine, pain after urination, urinary frequency and dribbling. However, these signs and symptoms are not specific to bladder cancer, and may also be caused by non-cancerous conditions, including prostate infections and cystitis.
Types of Bladder Cancer
Cancers are divided into superficial and invasive disease. Superficial bladder cancer is limited to the innermost linings of the bladder. Invasive bladder cancer has at least penetrated the muscular layer of the bladder wall. Less than 5% of bladder cancers in the United States are squamous cell carcinomas, however, worldwide this is the most common form, accounting for 75% of bladder carcinoma in underdeveloped nations. Urothelial carcinoma (transitional cell carcinoma) is by far the most common type of bladder cancer in the United States.
Diagnosis of Bladder Cancer
Cancer in the bladder is usually curable if it is diagnosed while the cancer is still contained in the bladder, and up to 80% of tumors are diagnosed at this early stage. A biopsy for bladder cancer is usually done during cystoscopy. CT and Ultrasound scans, urinalysis and arteriography may also be done.
Treatment for Bladder Cancer
Treatments include bladder cancer surgery, radiation, chemotherapy and biologic therapy. The stage and grade of the cancer provides important information and can help guide treatment. Superficial bladder tumors are surgically removed with chemotherapy being added to the treatment regime to help prevent recurrence. Radical cystectomy and urinary diversion (an external bag) is usually undertaken for invasive bladder cancer.
Several new compounds have shown activity against transitional cell bladder cancer and are now being tested in combination chemotherapy trials. BCG immunotherapy is the most effective intravesical therapy and involves a live attenuated strain of Mycobacterium bovis. Immunotherapy in the form of BCG instillation is also used to treat and prevent the recurrence of superficial tumors. Alternative bladder cancer treatments such as herbal treatment may also be of some benefit.
Stopping smoking can reduce the risk of getting bladder cancer and if you have been diagnosed with superficial bladder cancer, stopping smoking will reduce the risk of developing more tumours in the future. Bladder cancer has a recurrence rate of 50%-80% and therefore, doctors recommend cystoscopy screening every three months for the first two years after treatment. People who drink a lot of fluids each day have a lower rate of bladder cancer.
The prognosis depends on the stage of the cancer, whether it is superficial or invasive bladder cancer, and whether it has spread to other places in the body. Superficial bladder cancer has a good prognosis, with 5-year survival rates of 82-100%. If a tumor has grown into the wall of the bladder but has not spread to other organs, treatment usually involves surgical removal of the tumor, or combined chemotherapy and radiation therapy, with a five-year survival rate of 60% to 75%. Patients with more deeply invasive tumors,which are also usually less well differentiated, and those with lymphovascular invasion experience 5-year survival rates of 30% to 50% following radical cystectomy.